In U.S. Pat. application Ser. No. 08/549,976 a fibrous cell structure for fabrication of batteries was disclosed. The fibrous geometry of the cells described provides an extremely high surface area to volume ratio when multitude of small fibers are packed into a given volume. In general, the smaller the fiber OD (outside diameter), the higher the surface area. The high surface area available to electrodes translates into a higher number of active sites participating in the electrochemical reaction, hence, giving rise to higher energy density batteries. This concept is true for all electrochemical cells. For energy producing electrochemical cells such as full cells, the high surface area to volume ratio, similar to batteries results in higher energy density. For electrochemical cells that produce a product, this results in lower energy requirement. In addition, the high surface area available to the electrocatalyst reduces the requirement of the unused bulk quantities on the electrodes, and further reduces the material and fabrication cost of the cells.
It is an object of this invention to provide a structure for fabricating electrochemical cells that have fibrous geometry and can be made with fibrous electrodes ranging in size between about 10 micron to about 10 millimeter.
It is also an object of this invention to incorporate the fibrous cells into various electrochemical cell designs for fabricating batteries, fuel cells or other electrochemical reaction cells.